Studies of growth bands in Si:Ge crystals

Si:Ge crystals with approximately 3% of germanium were studied with various topographic methods using both conventional and synchrotron sources of X-rays. The present investigation included various types of white beam synchrotron topography and conventional Lang topographic methods. The topographic results obtained with various methods were dominated by strong contrast coming from growth bands. The Bragg-case section topographs with the beam front limited to 5 μm revealed the distribution of growth bands inside the crystals. Thanks to the low glancing angle the section topographs provided many information about the shape of growth surface despite small thickness of investigated wafers. Additionally taking the topographs at very large film-to-crystal distances it was possible to reveal the character of lattice deformation across the striations and to draw information about germanium distribution.